FACT Surface Technology for the Environment: An Adhesive Bonding Process Without Wet-Chemicals

With Freudenberg Adhesive Clean Technology (FACT), Freudenberg Sealing Technologies is introducing a new process for the surface treatment of metal parts. This adhesive bonding process enables bonds between elastomers and substrate parts made of ferrous metals, non-ferrous metals, and a wide variety of plastics. The fully automated manufacturing process is characterized by its resource-saving and cost efficiency as well as design flexibility. Materials can be bonded regardless of their layer thicknesses and functional surfaces. Unrestricted weldability, electrical conductivity, and resistance to AdBlue™ and other media open up a wide range of new applications.

With this process, the surfaces of the components can be permanently modified at the microscopic level without the use of solvents or binders. They are immediately ready for vulcanization or the bonding of elastomers. This results in another pivotal advantage of this new technology: the increased manufacturing efficiency reduces the Total Cost of Ownership (TCO) for the customer.

Elimination of wet-chemical bonding significantly improves environmental footprint without compromising the quality
"Until now, the use of wet-chemical bonding has been essential for bonding metal parts and that is why we have consistently driven this initiative forward within Freudenberg between Freudenberg Technology Innovation and Freudenberg Sealing Technologies," said Dominik Langore, Manager Surface Technology EU, Freudenberg Sealing Technologies, T&I.

The company's intensive research work has now proven its worth and reached market maturity. With FACT, the environmental impact of the coating process is significantly reduced. A key factor in the products' environmental footprint is the elimination of solvents, which were previously required in the material formulations. Even the binders, which previously could contain more than 90 percent solvents, are no longer necessary. This eliminates the need for a wide range of substances that are potentially hazardous to health and the environment.

By eliminating these process steps, the material and energy consumption of the pretreatment process is significantly reduced, which in turn results in a significantly lower CO2 footprint for the product line. In a life cycle assessment, the CO2 emissions of a reference process were tested for three coating methods. The most emission-intensive wet chemical process was taken as the 100 percent reference value. A comparative process using a different binder caused 65.2 percent of the reference emissions. With FACT, CO2 emissions can be reduced to 1.1 percent of the reference value.

"With every process step we eliminate using our new binding technology, we also reduce the number of potential errors throughout the entire manufacturing process," Langore added. "From a supply chain perspective, this is advantageous because the required components are multi-sourced and thus not subject to single-source dependency."

Tailored to the application: FACT broadens the range
Thanks to its excellent resistance to oils, water, hydrogen (H?), and AdBlue™, the FACT coating process enables the use of elastomers in combinations with metals and plastics that were previously not possible. The adhesion and flexibility of the coated metal substrates are maintained even under high loads and at temperatures as low as -40 °C, without forming microcracks. Additionally, online process monitoring ensures the traceability and quality of the manufactured components.

This cost-efficient process opens up a wide range of potential applications, covering virtually all motorized drive and energy storage systems on the roads, at sea, and in aviation. Its use in battery technologies - for example, in e-bikes - is now also feasible.

"In close collaboration with our customers, cross-industry and cross-departmental exchange often generates the most innovative ideas," said Langore. "With FACT, we have created an excellent foundation for developing a wide range of durable applications using a groundbreaking bonding process and new material combinations."